Percutaneous VAD Offers Hope for Severe Refractory Cardiogenic-Shock Patients

Reed Miller

October 21, 2010

October 21, 2010 (Houston, Texas) — A new study shows percutaneous ventricular assist devices (pVADs) may provide a ray of light for a group of patients with an otherwise dark prognosis [1].

Patients with ischemic cardiomyopathy and cardiogenic shock have a short-term mortality rate between 55% and 73%. Counterpulsation with an intra-aortic balloon pump (IABP), the most common treatment for these patients, often cannot reverse hemodynamic compromise in these patients, and trials of surgically placed left ventricular assist devices (LVADs) in this population have shown high complication rates, Dr Biswajit Kar (Texas Heart Institute, Houston) explained to heartwire .

The hemodynamic data on the TandemHeart pVAD (CardiacAssist) device impressed Kar and his colleagues enough that they began percutaneously implanting the pump in patients with severe refractory cardiogenic shock (SRCS) in their cath lab. Results from their experience with the pVAD, showing that it can "bridge the gap" between IABP and LVAD support in this population, are published online October 8, 2010 in the Journal of the American College of Cardiology.

Of the 117 patients in their study, 80 patients had ischemic and 37 patients had nonischemic cardiomyopathy. The average duration of support with the device was 5.8 days. After implantation, the cardiac index improved from a median of 0.52 to 3.0 (p<0.001), systolic blood pressure increased from 75 mm Hg to 100 mm Hg (p<0.001), and pulmonary capillary wedge pressure, lactic-acid level, and creatinine level all decreased significantly.

The mortality rates at 30 days and six months were 40.2% and 45.3%, respectively. "Since our study was not randomized, we can't claim to show a 'mortality benefit,' " Kar said. "However, compared with the dismal outcomes of patients with similar hemodynamic parameters in other studies--it appears to improve survival."

The researchers' analysis of survivors vs nonsurvivors shows the cause of death was either superimposed infection or irreversible end-organ damage and subsequent multisystem organ failure. After device placement, eight patients were discovered to have a neurological insult/stroke, of which three had the pVAD replaced and later survived to discharge; 31 patients had multiorgan failure, of which 14 survived to discharge, with three undergoing transplantation and four being transitioned to other LVADs.

Of the 21 patients who did not receive an IABP before pVAD placement, 15 were alive at six months despite undergoing cardiopulmonary resuscitation (CPR) at the time of device placement. Twenty-four of the 56 patients with SRCS who underwent pVAD placement while undergoing active CPR survived for at least 30 days. This illustrates the efficacy of the pVAD in reestablishing end-organ perfusion and suggests that earlier placement of the pVAD might have further decreased the total mortality rate, the authors conclude. Earlier placement of the device in SRCS patients should be tested in further trials, they add.